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From: Li Zefan <lizefan@huawei.com>
To: Tejun Heo <tj@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>, cgroups <cgroups@vger.kernel.org>
Subject: [PATCH v2 02/12] cpuset: update cpuset->effective_{cpus,mems} at hotplug
Date: Fri, 11 Oct 2013 17:49:48 +0800	[thread overview]
Message-ID: <5257C9BC.8000509@huawei.com> (raw)
In-Reply-To: <5257C9A1.1030404@huawei.com>

We're going to have separate user-configured masks and effective ones.

Eventually configured masks can only be changed by writing cpuset.cpus
and cpuset.mems, and they won't be restricted by parent cpuset. While
effective masks reflect cpu/memory hotplug and hierachical restriction,
and these are the real masks that apply to the tasks in the cpuset.

We calculate effective mask this way:
  - top cpuset's effective_mask == online_mask, otherwise
  - cpuset's effective_mask == configured_mask & parent effective_mask,
    if the result is empty, it inherits parent effective mask.

Those behavior changes are for sane_behavior only. For !sane_behavior
effective_mask and configured_mask are the same, so we won't break old
interfaces.

To make cs->effective_{cpus,mems} to be effective masks, we need to
  - change the effective masks at hotplug
  - change the effective masks at config change
  - take on ancestor's mask when the effective mask is empty

The first item is done here.

This won't introduce behavior change.

Signed-off-by: Li Zefan <lizefan@huawei.com>
---
 kernel/cpuset.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index e13fc2a..d0ccde2 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2186,6 +2186,7 @@ retry:
 
 	mutex_lock(&callback_mutex);
 	cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, &off_cpus);
+	cpumask_andnot(cs->effective_cpus, cs->effective_cpus, &off_cpus);
 	mutex_unlock(&callback_mutex);
 
 	/*
@@ -2200,6 +2201,7 @@ retry:
 
 	mutex_lock(&callback_mutex);
 	nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems);
+	nodes_andnot(cs->effective_mems, cs->effective_mems, off_mems);
 	mutex_unlock(&callback_mutex);
 
 	/*
@@ -2263,6 +2265,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
 	if (cpus_updated) {
 		mutex_lock(&callback_mutex);
 		cpumask_copy(top_cpuset.cpus_allowed, &new_cpus);
+		cpumask_copy(top_cpuset.effective_cpus, &new_cpus);
 		mutex_unlock(&callback_mutex);
 		/* we don't mess with cpumasks of tasks in top_cpuset */
 	}
@@ -2271,6 +2274,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
 	if (mems_updated) {
 		mutex_lock(&callback_mutex);
 		top_cpuset.mems_allowed = new_mems;
+		top_cpuset.effective_mems = new_mems;
 		mutex_unlock(&callback_mutex);
 		update_tasks_nodemask(&top_cpuset, NULL);
 	}
-- 
1.8.0.2


  parent reply	other threads:[~2013-10-11  9:49 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-11  9:49 [PATCH v2 00/12] cpuset: separate configured masks and effective masks Li Zefan
2013-10-11  9:49 ` [PATCH v2 01/12] cpuset: add cs->effective_cpus and cs->effective_mems Li Zefan
2013-10-11  9:49 ` Li Zefan [this message]
2013-10-11  9:50 ` [PATCH v2 03/12] cpuset: update cs->effective_{cpus,mems} when config changes Li Zefan
2013-10-15 15:18   ` Tejun Heo
2013-10-11  9:50 ` [PATCH v2 04/12] cpuset: inherit ancestor's masks if effective_{cpus,mems} becomes empty Li Zefan
2013-10-11  9:50 ` [PATCH v2 05/12] cpuset: use effective cpumask to build sched domains Li Zefan
2013-10-15 15:25   ` Tejun Heo
2013-10-11  9:50 ` [PATCH v2 06/12] cpuset: initialize top_cpuset's configured masks at mount Li Zefan
2013-10-11  9:51 ` [PATCH v2 07/12] cpuset: apply cs->effective_{cpus,mems} Li Zefan
2013-10-11  9:51 ` [PATCH v2 08/12] cpuset: make cs->{cpus,mems}_allowed as user-configured masks Li Zefan
2013-10-11  9:51 ` [PATCH v2 09/12] cpuset: refactor cpuset_hotplug_update_tasks() Li Zefan
2013-10-11  9:51 ` [PATCH v2 10/12] cpuset: enable onlined cpu/node in effective masks Li Zefan
2013-10-11  9:51 ` [PATCH v2 11/12] cpuset: allow writing offlined masks to cpuset.cpus/mems Li Zefan
2013-10-15 15:36   ` Tejun Heo
2013-10-11  9:52 ` [PATCH v2 12/12] cpuset: export effective masks to userspace Li Zefan

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